The objective of this application is the development of a small, high- speed, modulated xy scanner for the photocoagulation treatment of individual portwine stain and telangiectases microvessels. Despite significant progress, an ideal device for selective photocoagulation of abnormal skin microvessels as in portwine stains and telangiectases still does not exist. A small, high speed, modulated xy scanner for treatment of individual vessels will be developed,a nd verified and optimized in animal studies. By individually and rapidly acquiring and photocoagulating microvessels, the device design simultaneously reduces laser power requirements and increases the flexibility of treatment parameters in comparison with all existing surgical lasers for dermatology. A 0.2 mm uniform laser beam spot will be rapidly scanned and commanded in real time to stop and dwell for a user-defined time as low as 2 msec, based on detection of vessels via user-defined confocal reflectance thresholds. Because selective photocoagulation achieved by direct optical targeting, it will be possible to use inexpensive, penetrating near-infrared lasers in addition to or instead of the high-power visible lasers now in use to treat these lesions. The project is a new collaboration between optical scanning and medical laser research experts.